Stream-side plantings and ecosystem services

What do dairy farmers think about planting riparian margins?

Key messages:

We surveyed Taranaki dairy farmers on their perceptions of the value of riparian plantings

They reported many different values with the plantings; some positive, some negative

Farmers who carried out riparian plantings reported improvement to both farm performance and the environment

Over two stormy days in 2015, a group of dairy farmers working on the Taranaki ring plain in New Zealand left their flooding paddocks to gather at the Stratford Multisports Centre. They had been invited to participate in an interactive meeting with the purpose of describing their experiences and views on the costs and benefits of planting riparian margins on their farms (Maseyk et al, 2017).

Following European settlement in the mid-1800s, the once forested plains around Mt Taranaki (one of New Zealand’s most iconic volcanoes) were rapidly converted into a pastoral landscape dominated by exotic pasture species. This transformation made Taranaki a nationally important dairy region. In the process, native vegetation was reduced to less than 10% of its former cover. The benefit of food production had come at a considerable cost to native biodiversity and the provision of a range of other ecosystem services.

In 1993 the Taranaki Regional Council initiated a voluntary planting program to restore vegetation to riparian margins with an aim of maintaining water quality. Twenty years on, we were interested in finding out how farmers perceive the costs and benefits of undertaking riparian planting.

Two groups of farmers participated in the meetings; Group A (17 farmers) who have or are implementing riparian planting and Group B (five farmers) who have fenced, but not planted their riparian margins (Figure 1).

Figure 1: Group A farmers opted for planted margins (image on the left shows multi-tier planted margins) whereas Group B farmers used fenced grass strip margins (as pictured on the right). (Image on the left and at top by Fleur Maseyk; image on the right Taranaki Regional Council.)

Not surprisingly, the two groups of farmers had quite different perspectives, with Group A perceiving 21 positive aspects and 11 negative aspects associated with riparian margin plantings, and Group B perceiving only 15 aspects, all of which were negative. These pros and cons fell across production, environmental, and social values (Figure 2), and show that our participant farmers are thinking about additional ecosystem services and benefits beyond water quality as well as trade-offs.

The writing is on the wall: Taranaki dairy farmers review the issues regarding riparian margins raised during the group discussion. The question they asked themselves was: “Which of these are most important to me?” (Image by Fleur Maseyk)

From our structured discussions we found that while Group A identified many benefits from planting riparian margins, they also shared some common ground with Group B in recognising associated costs and liabilities, such as the loss of production land, and increased weeds and pests. However, Group A suggested that many of these issues can be balanced by positive aspects of riparian margin plantings. For example, they observed that cows will graze longer in the shade provided by riparian plantings (which means more milk) and this can be enough to make up for the loss of production land.

In contrast to Group A, Group B farmers were disinclined to plant their riparian margins as they did not think there were any additional benefits to be gained that could not be achieved by fenced-only (grass strip) margins. Indeed, both groups observed that fencing excludes livestock from waterways, and allows for greater precision mapping of the farm, improved rotational grazing, and better allocation of feed. The farmers observed that not only did fences prevent their lifestock from falling into, or getting stuck in waterways, they saved them money (by avoiding lifestock injury or loss, labour time to retrieve animals, and damage to farm equipment used in retrieval), and increased the safety of farm staff who were no longer retrieving animals from waterways.

Critically, Group B identified that neither grass strip or planted multi-tier riparian margins can address sub-surface nutrient flows. Consequently, this group of farmers felt the objective of the planting program — to protect water quality — was misguided, and this view obscured the recognition of all other potential values and benefits of planting riparian margins and prevented them from implementing planting on their farms.

However, we found that farmers who had planted as well as fenced riparian margins experienced increased benefits for both farm peformance and environmental enhancement.

Figure 2: The pros and cons of fenced-only grass strip riparian margins (Panel A) and fenced and riparian margins (Panel B) as identified by Taranaki ring plain dairy farmers. Individual attributes of riparian margins can contribute values across the board, for example, a well managed farm attracts better staff which is shown here as a social value, but also ultimately contributes to productivity of the farm and “more milk in the vat”.